Answer:
A thermochemical equation for the combustion of propane (C3H8)(C3H8) is written as follows:
C3H8(l)+5O2(g)→3CO2(g)+4H2O(g);ΔH∘rxnC3H8(l)+5O2(g)→3CO2(g)+4H2O(g);ΔHrxn∘ = -2202.0 kJ/mol
The value given for ΔH∘rxnΔHrxn∘ means that:
a. the reaction of one mole of propane absorbs 2202 kJ of energy from the surroundings.
b. the reaction is endothermic.
c. the enthalpy of formation of propane is 2202 kJ/mol.
d. the reaction of one mole of propane releases 2202 kJ of energy to the surroundings.
e. None of these.
Answer:
8.13 ×10²³ atoms
Explanation:
Given data:
Mass of magnesium = 32.45 g
Number of atoms = ?
Solution:
Number of moles of Mg:
Number of moles = mass/molar mass
Number of moles = 32.45 g/ 24 g/mol
Number of moles = 1.35 mol
Number of atoms:
1 mole contain 6.022×10²³ atoms
1.35 mol × 6.022×10²³ atoms/ 1mol
8.13 ×10²³ atoms
In an exothermic reaction, heat is transferred to the surrounding.
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Answer:
m = 671 grams
Explanation:
Given that,
No of moles, n = 4.9
Molar mass of Barium, M = 137 g
Mass divided by molar mass is equal to no of moles. It can be given by the formula as follows :

or
m = 671 grams
So, the total mass of the sample of Barium is 671 grams.
Answer:
It is at the greater angle (higher solar elevation) that the surface area receives the most energy because the rays are spread out less. ... The smaller the elevation angle (30°, 20°, 10°) the less energy received per square centimeter, because the rays spread out over a greater area.
Explanation:
correct me if I'm wrong